खनिज तथा ऊर्जा संसाधन Class 10 | Manganese, Copper and Aluminum | Mineral and Energy Resources

Class 10 Social Science | Contemporary India | Chapter 5 Minerals and Energy Resources | Important Questions and Quick Revision |

Hazards Of Mining|Conservation Of Minerals|Energy Resources|OMR|Summary

Class 10 Science | Chapter 16 Management of Natural Resources

Introduction|Mode of Occurrence of Minerals|Classification of Minerals|Conservation of Energy Resources|Summary

Class 10 Social Science | Contemporary India | Forest and Wildlife Resources | Important Questions and Quick Revision |

Light of wavelength 2000 Å falls on an aluminium surface . In aluminium 4.2 e V of energy is required to remove an electron from its surface. What is the kinetic energy , in electron volt of (a) the fastest and (b) the slowest emitted photo-electron . ( c) What is the stopping potential ? (d) What is the cut - off wavelength for aluminum? (Plank's constant h = 6.6 xx 10^(-34) J-s and speed of light c = 3 xx 10^(8) m s^(-1).

Class 10 Science | Chapter 14 Sources of Energy | Important Question and Quick Revision

Minerals, metals, and fossil fuels are which type of resources of energy?

A copper block of mass 1kg slides down one rough inclined plane of inclination 37^(@) at a constant speed. Find the increase in the temperature of the block as it slides down temperature of the block as it slides down through 60cm assuming that the loss in mechanical energy goes into the copper block as thermal energy. (specific heat of copper= 420Jkg^(-1)K^(-1),g=10ms^(-2) )